versioncmp: pass full tagnames to swap_prereleases()
[git/git.git] / versioncmp.c
CommitLineData
9ef176b5 1#include "cache.h"
d811c8e1 2#include "string-list.h"
9ef176b5
NTND
3
4/*
5 * versioncmp(): copied from string/strverscmp.c in glibc commit
6 * ee9247c38a8def24a59eb5cfb7196a98bef8cfdc, reformatted to Git coding
7 * style. The implementation is under LGPL-2.1 and Git relicenses it
8 * to GPLv2.
9 */
10
11/*
12 * states: S_N: normal, S_I: comparing integral part, S_F: comparing
13 * fractionnal parts, S_Z: idem but with leading Zeroes only
14 */
15#define S_N 0x0
16#define S_I 0x3
17#define S_F 0x6
18#define S_Z 0x9
19
20/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
21#define CMP 2
22#define LEN 3
23
d811c8e1
NTND
24static const struct string_list *prereleases;
25static int initialized;
26
27/*
109064a0
SG
28 * off is the offset of the first different character in the two strings
29 * s1 and s2. If either s1 or s2 contains a prerelease suffix starting
30 * at that offset, it will be forced to be on top.
d811c8e1 31 *
109064a0
SG
32 * If both s1 and s2 contain a (different) suffix at that position,
33 * their order is determined by the order of those two suffixes in the
34 * configuration.
d811c8e1
NTND
35 *
36 * Return non-zero if *diff contains the return value for versioncmp()
37 */
109064a0
SG
38static int swap_prereleases(const char *s1,
39 const char *s2,
40 int off,
d811c8e1
NTND
41 int *diff)
42{
d811c8e1
NTND
43 int i, i1 = -1, i2 = -1;
44
45 for (i = 0; i < prereleases->nr; i++) {
46 const char *suffix = prereleases->items[i].string;
109064a0 47 if (i1 == -1 && starts_with(s1 + off, suffix))
d811c8e1 48 i1 = i;
109064a0 49 if (i2 == -1 && starts_with(s2 + off, suffix))
d811c8e1
NTND
50 i2 = i;
51 }
52 if (i1 == -1 && i2 == -1)
53 return 0;
54 if (i1 >= 0 && i2 >= 0)
55 *diff = i1 - i2;
56 else if (i1 >= 0)
57 *diff = -1;
58 else /* if (i2 >= 0) */
59 *diff = 1;
60 return 1;
61}
9ef176b5
NTND
62
63/*
64 * Compare S1 and S2 as strings holding indices/version numbers,
65 * returning less than, equal to or greater than zero if S1 is less
66 * than, equal to or greater than S2 (for more info, see the texinfo
67 * doc).
68 */
69
70int versioncmp(const char *s1, const char *s2)
71{
72 const unsigned char *p1 = (const unsigned char *) s1;
73 const unsigned char *p2 = (const unsigned char *) s2;
74 unsigned char c1, c2;
75 int state, diff;
76
77 /*
78 * Symbol(s) 0 [1-9] others
79 * Transition (10) 0 (01) d (00) x
80 */
81 static const uint8_t next_state[] = {
82 /* state x d 0 */
83 /* S_N */ S_N, S_I, S_Z,
84 /* S_I */ S_N, S_I, S_I,
85 /* S_F */ S_N, S_F, S_F,
86 /* S_Z */ S_N, S_F, S_Z
87 };
88
89 static const int8_t result_type[] = {
90 /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */
91
92 /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
93 /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN,
94 /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
95 /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP
96 };
97
98 if (p1 == p2)
99 return 0;
100
101 c1 = *p1++;
102 c2 = *p2++;
103 /* Hint: '0' is a digit too. */
104 state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
105
106 while ((diff = c1 - c2) == 0) {
107 if (c1 == '\0')
108 return diff;
109
110 state = next_state[state];
111 c1 = *p1++;
112 c2 = *p2++;
113 state += (c1 == '0') + (isdigit (c1) != 0);
114 }
115
d811c8e1
NTND
116 if (!initialized) {
117 initialized = 1;
118 prereleases = git_config_get_value_multi("versionsort.prereleasesuffix");
119 }
109064a0
SG
120 if (prereleases && swap_prereleases(s1, s2, (const char *) p1 - s1 - 1,
121 &diff))
d811c8e1
NTND
122 return diff;
123
9ef176b5
NTND
124 state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
125
126 switch (state) {
127 case CMP:
128 return diff;
129
130 case LEN:
131 while (isdigit (*p1++))
132 if (!isdigit (*p2++))
133 return 1;
134
135 return isdigit (*p2) ? -1 : diff;
136
137 default:
138 return state;
139 }
140}